SINTESIS TURUNAN PIRAZOLINA SEBAGAI AGEN ANTIBAKTERI DARI VANILIN DAN MINYAK GANDAPURA

AMRI SETYAWATI, Dra. Tutik Dwi Wahyuningsih, M.Si. Ph.D.; Drs. Bambang Purwono, M.Sc., Ph.D.

2015 | Tesis | S2 Ilmu Kimia

Telah disintesis senyawa turunan pirazolina (3a-3b) dan benzohidrazida (3c) dari 5-bromovanilin (1) melalui senyawa antara kalkon (2), serta uji aktivitasnya sebagai antibakteri dengan metode difusi. Pirazolina disintesis dari bahan awal vanilin, sedangkan benzohidrazida disintesis dari bahan awal vanilin dan minyak gandapura. Pirazolina 3adisintesis dengan mereaksikan kalkon dan hidrazin monohidrat melalui refluks dalam metanol, sedangkan N-asetil pirazolina 3b direfluks dalam asam asetat glasial. Benzohidrazida terbentuk dari pengadukan kalkon dengan salisil hidrazin pada suhu ruang. Semua produk sintesis dianalisis strukturnya dengan spektrometer FTIR, GC-MS, 1H- dan13C-NMR. Pirazolina dan benzohidrazida hasil sintesis kemudian diuji aktivitasnya sebagai agen antibakteri terhadap 3 bakteri Gram positif (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus) dan 2 bakteri Gram negatif (Escherichia coli, Shigella flexnerri) dengan tetrasiklin sebagai kontrol positif dan DMSO 99,99% sebagai kontrol negatif. Hasil penelitian menunjukkan bahwa 5-bromovanillin (1), kalkon (2), pirazolina (3a), pirazolina (3b), dan benzohidrazida (3c) diperoleh dengan rendemen secara berurutan sebesar 98, 78, 87, 88 dan 33%. Seluruh senyawa uji menunjukkan aktivitas antibakteri dengan spektrum luas dan pirazolina (3b) menunjukkan peningkatan aktivitas antibakteri pada Gram positif. Aktivitas antibakteri tertinggi pirazolina dicapai oleh pirazolina (3b) melawan bakteri Staphylococcus aureus (1000 ppm: 7,25 mm), sedangkan benzohidrazida pada bakteri Bacillus subtilis (1000 ppm: 7,62 mm)

The pyrazoline derivatives (3a-3b) and benzohydrazide (3c) have been synthesized from 5-bromovanillin (1) through chalcone intermediate (2). They have been tested as antibacterial agents by diffusion method. Pyrazolines were produced from vanillin while benzohydrazide was produced from wintergreen oil. Pyrazoline 3a was synthesized by refluxing chalcone with hydrazine monohydrate in methanol, while N-acetyl pyrazoline 3b was refluxed in glacial acetic acid. Benzohydrazide was formed by stirring chalcone and salicyl hydrazine at room temperature. The structure of all products was elucidated by spectrometers FTIR, GCMS, 1H- and 13C-NMR. Pyrazolines and benzohydrazide products were tested as antibacterial agents to against growth of Staphylococcus aureus, Bacillus subtilis, Bacillus cereus (Gram positive) and Escherichia coli, Shigella flexnerri (Gram negative) with tetracycline as positive control and DMSO 99.99% as negative control. The result showed that 5-bromovanillin (1), chalcone (2), pyrazoline (3a), pyrazoline (3b) and benzohydrazide (3c) were produced in 98, 78, 87, 88, and 33% yield, respectively. All of the tested compounds showed antibacterial activity in broad spectrum and pyrazoline (3b) showed increasing antibacterial activity for Gram positive. The highest antibacterial activity of pyrazoline was obtained by pyrazoline (3b) to against Staphylococcus aureus (1000 ppm: 7.25 mm) while benzohydrazide at (3c) for Bacillus subtilis (1000 ppm: 7.62 mm).

Kata Kunci : Vanillin, Chalcone, Pyrazoline, Antibacterial